If you like to think of LotR in geographical terms. I prefer her cartographical style to Fonstad, though Fonstad's documentation of her research is worth the price of her book.

However, you have to take Strachey with a grain of salt: anything that she puts in (like contour lines, woods, etc.) that aren't from the book are her inventions, to give the maps a realistic look. Her guesses and additions are well-thought-out and consistent with what is written, mostly, but they are by no means authorized by Tolkien.

If you compare her contour lines (for instance) with real-world examples, though, you'll find that she portrays a very simplified landscape indeed, much the way Tolkien did.

this new edition came out with the release of the LOTR three-volume set by geoff taylor a few years ago. you can see his covers here: http://www.geofftaylor.btinternet.co.uk/gallerytolkien.htmlclick on the thumbnails to get the full cover -- kinda neat how he combined them. "Alas for us all! And for all that walk the world in these after-days. For such is the way of it: to find and lose, as it seems to those whose boat is on the running stream. But I count you blessed, Gimli son of Glóin: for your loss you suffer of your own free will, and you might have chosen otherwise. But you have not forsaken your companions, and the least reward that you shall have is that the memory of Lothlórien shall remain ever clear and unstained in your heart, and shall neither fade nor grow stale."

It is worth it, though as squire notes, there are some who quibble with some of Strachey's choices and she does take some liberties.

Fonstad's Atlas is perhaps the best map book on Tolkien, but the colors and the layout of the LOTR maps makes it more difficult to consult. Strachey's book is better if you want to follow the path of the Fellowship in more detail. Now Fonstad adds invaluable First Age maps of the battles of Beleriand, etc., so there is a lot of added value to her book if you want to go outside the LOTR geography. (Formerly drogo of the two names!)

As a person who finds it very hard to visualise the journey across Middle-Earth (or the journey to the nearby shops for that matter) I found this book extremely handy. It really helped me figure out how the different bits of the journey fit together, rather than staring silently and hopelessly at the maps inside LOTR in despair.